1. Field of the Invention
The present invention relates to the valve of a vacuum apparatus which is provided between both left and right vacuum chambers which open and close an opening therebetween.
2. Description of the Related Art
Generally, the valve of a vacuum apparatus which is used for producing semiconductors, etc., to open and close vacuum chambers is shown in FIG. 1. In between right and left vacuum chambers 80 and 81, a valve V0is provided vertically. This valve V0has a casing C, in which a valve body 86 is accommodated movably in its upper and lower directions. The valve body 86 is formed in a plate-like shape and fixed at the upper end of a valve shaft 84.
The valve shaft 84 slides in a seal S0and a bellows 85 is formed between the seal S0and the upper end of the valve shaft 84 to maintain a vacuum state in the casing C while the valve shaft 84 slides. A driving section (not shown) is formed under the valve shaft 84 so that the valve body 86 moves up and down to open and close the communicating aperture 82 of the casing C.
However, in the valve V0of the vacuum apparatus, since the bellows 85 which is placed inside a communicating space S1of both vacuum chambers 80 and 81 is expanded and shrunken in a vacuum situation, life span of the bellows 85 is short and harmful particles are generated. Moreover, a plate type of valve body is used in the valve V0, and therefore it can only seal one side of the vacuum chamber 80. Furthermore, there is a problem that the working space is limited to make difficult maintenance work for the driving section because the valve V0is fitted vertically in between the two vacuum chambers 80 and 81 with the driving section being positioned under the two chambers.